This portion of a nephron functions to control the amount of water in urine so that concentrated urine is produced when one is dehydrated -(low blood volume/pressure) or dilute urine is produced when one is overhydrated(high blood volume/pressure).

the correct answer is:

This portion of a nephron functions to control the amount of water in urine so that concentrated urine is produced when one is dehydrated distal convoluted tube-(low blood volume/pressure) or dilute urine is produced when one is overhydrated ascending and descending limbs of the Loop of Henle (high blood volume/pressure).

Explanation:

The kidneys are responsible for the production of urine through the mechanisms of ultrafiltration, tubular reabsorption and tubular secretion. Depending on the need for water, either dehydrated or hydrated state, a concentrated and small volume or dilute and large volume urine is produced, in order to maintain the relative water balance of the kidneys.

The nephron is the functional unit of the kidneys.

Now, let me explain how concentrated and dilute urine are produced;

Dilute Urine: Dilute urine is a urine with a high water content. The need to excrete a large volume of water occurs when the water content of the blood is high resulting in high blood volume (hypervolemia) or high blood pressure, hence, to bring back the pressure and volume of blood to normal level, the body gets rid of excess water through the urine. The process of dilution of urine is brought about by the counter-current mechanism in the renal medulla. The concentration of the Renal Medulla increases progressively along with the descending limb of the Loop of Henle. The tubular filtrate flow in opposite directions as the Loop descends and ascends, creating a counter-current mechanism. as the fluid in the compartment of the Henle's Loop ascends, NaCl is excreted into the interstitial spaces, increasing the interstitial solute concentration, at the same time the loop is impermeable to water, making the fluid in the distal ascending limb of the loop to be dilute, and the remaining part of the nephron is impermeable to water hence a large volume of dilute urine is excreted.

Concentrated urine: The need for concentrated urine arises when the water content of the blood is low, resulting in low blood volume/pressure. Hence, the need to excrete a small volume of water in the urine, resulting in  a small urine volume that is concentrated. The concentration is brought about by the reabsorption of water in the distal convoluted tubule and the collecting duct. These regions become permeable to water under the influence of the hormone Vasopressin which is secreted in a dehydrated state.

really dont know just need some points

an individual’s sex (i.e., whether they are a male or female) is determined by the sex chromosomes. most people have two sex chromosomes, one that is inherited from their mother and one that is inherited from their father. typically, females have two x chromosomes (xx) and males have one x chromosome and one y chromosome (xy). conditions caused by changes (“mutations”) in genes located on the x chromosome are considered x-linked.

x-linked recessive inheritance

most x-linked conditions are recessive. this means that in a person with two x chromosomes (most females), both copies of a gene (i.e., one on each x chromosome) must have a change or mutation whereas in a person with one x chromosome (most males), only one copy of a gene must have a mutation. a female with a mutation in one copy of a gene on the x chromosome is said to be a “carrier” for an x-linked condition. a male with a mutation in a gene on the x chromosome is typically affected with the condition. because females have two copies of the x chromosome and males have only one x chromosome, x-linked recessive diseases are more common among males than females. however, x-linked recessive diseases can occur in both males and females.

for x-linked recessive disorders, an unaffected carrier mother who has a mutation in a gene on the x chromosome can transmit either the x chromosome with this mutation or a “normal” x chromosome to her children. if the father is unaffected, none of her daughters will be affected and all of her daughters will be unaffected—since they will inherit at least one normal x chromosome from their father. however, each daughter will have a 50% chance of being an unaffected carrier like her mother and a 50% chance of both x chromosomes being normal.